Single Inclusive Distribution and Two-Particle Correlations Inside One Jet at "Modified Leading Logarithmic Approximation" of Quantum Chromodynamics II : Steepest Descent Evaluation at Small X

The MLLA single inclusive distribution inside one high energy (gluon) jet at small x is estimated by the steepest descent method. Its analytical expression is obtained outside the "limiting spectrum". It is then used to evaluate 2-particle correlations at the same level of generality. The dependence of both observables on the ratio between the infrared cutoff Q\_0 and Lambda\_QCD is studied. Fong & Webber's results for correlations are recovered at the limits when this ratio goes to 1 and when one stays close to the peak of the single inclusive distribution.Comment: LaTeX, 22 pages, 18 .eps figure

Equilibrium of stellar dynamical systems in the context of the Vlasov-Poisson model

This short review is devoted to the problem of the equilibrium of stellar dynamical systems in the context of the Vlasov-Poisson model. In a first part we will review some classical problems posed by the application of the Vlasov-Poisson model to the astrophysical systems like globular clusters or galaxies. In a second part we will recall some recent numerical results which may give us some some quantitative hints about the equilibrium state associated to those systems.Comment: 8 pages, no figures, accepted in Communications in Nonlinear Science and Numerical Simulatio

The internal structure of jets at colliders: light and heavy quark inclusive hadronic distributions

In this paper, we report our results on charged hadron multiplicities of heavy quark initiated jets produced in high energy collisions. After implementing the so-called dead cone effect in QCD evolution equations, we find that the average multiplicity decreases significantly as compared to the massless case. Finally, we discuss on the transverse momentum distribution of light quark initiated jets and emphasize on the comparison between our predictions and CDF data.Comment: 6 pages, 3 figures-Talk presented by Redamy Perez-Ramos at Jets in Proton-Proton and Heavy-Ion Collisions, August 12-14, 2010, Prague, Czech Republi

Forward Flight Rotor Performance at Martian Atmospheric Densities and Sensitivity to Low Reynolds Numbers

Much effort has been made to enhance exploration on Mars. In addition to a rover and Mars-orbiting satellites, a Mars Helicopter Technology Demonstrator was proposed by the NASA Jet Propulsion Laboratory (JPL) to augment planetary research for the Mars 2020 Mission. Understanding rotor performance is vital for operations at Martian atmospheric conditions. The work presented is a study investigating rotor performance at Martian atmospheric conditions. Forward flight rotor tests were conducted in the Planetary Aeolian Laboratory (PAL) at NASA Ames Research Center, which has the capability to evacuate the air in the chamber to reach Martian atmospheric densities. A 1-meter-diameter rotor, roughly approximating the Mars Helicopter Technology Demonstrator, was tested at multiple atmospheric densities, including that of Mars. Rotor rotational speed, thrust, torque, power, and airspeed measurements were collected during the test. These results were then correlated with simulated cases using a mid-fidelity computational fluid dynamics software, Rotorcraft CFD (RotCFD). C81Generator (C81Gen) was used to generate airfoil aerodynamic coefficient for the spanwise locations along the rotor. To observe the differences between the C81Gen flow type modes at low Reynolds number, the simulations at Martian atmospheric densities were run under the fully turbulent, and the fully laminar flow type. In addition, Reynolds number effects (within 2x104 to 9x104) on experimental thrust coefficient, power coefficient, and figure of merit were analyzed. Within this chord- based Reynolds number range, CT and FM decreased around 26% and 36%, respectively, while CP remained fairly constant, exhibiting variations of no more than 5.5%. Despite the challenges involved in testing at a large difference of atmospheric ensities between Earth and Mars, repeatable data was obtained in all the measurements at Martian atmospheric conditions

Boundary terms in the Barrett-Crane spin foam model and consistent gluing

We extend the lattice gauge theory-type derivation of the Barrett-Crane spin foam model for quantum gravity to other choices of boundary conditions, resulting in different boundary terms, and re-analyze the gluing of 4-simplices in this context. This provides a consistency check of the previous derivation. Moreover we study and discuss some possible alternatives and variations that can be made to it and the resulting models.Comment: 10 pages, 2 figures, revtex; v2: typos in some formulas corrected, version appeared in journa

Stabilizing Entangled States with Quasi-Local Quantum Dynamical Semigroups

We provide a solution to the problem of determining whether a target pure state can be asymptotically prepared using dissipative Markovian dynamics under fixed locality constraints. Beside recovering existing results for a large class of physically relevant entangled states, our approach has the advantage of providing an explicit stabilization test solely based on the input state and constraints of the problem. Connections with the formalism of frustration-free parent Hamiltonians are discussed, as well as control implementations in terms of a switching output-feedback law.Comment: 11 pages, no figure

Finiteness of a spinfoam model for euclidean quantum general relativity

We prove that a certain spinfoam model for euclidean quantum general relativity, recently defined, is finite: all its all Feynman diagrams converge. The model is a variant of the Barrett-Crane model, and is defined in terms of a field theory over SO(4) X SO(4) X SO(4) X SO(4).Comment: 6 pages, 1 figur